A door jamb is the vertical portion of a door frame onto which a door is secured. Most types of door fasteners and deadbolts extend into a recess within the door jamb when in the locked position, making the strength of the door jamb and door frame vitally important to the overall security of the door.
Given an actual door width, the limited area on the door in which to install the dead bolt, and that the door itself is installed flush to the door jamb, the corresponding hole (recess) to accept the dead bolt ends up being located extremely close to the edge of the door jamb, making this area the weakest part of the door assembly. This is due to the fact that the remaining wood left between the recess and the edge of the door jamb is relativity small, in most cases just over ¼ inch
When the door is struck with a force, this force is transferred from the door to the dead bolt or latch bolt, which when inserted into the door jamb, transfers that force onto the wooden jamb With a large enough force, the door jamb breaks allowing forced entry to occur. Traditionally, in order to reinforce the jamb, a metal plate, called a strike plate, is mounted with screws onto the jamb itself vertically between the door jamb and the door The strike plate has an opening which is similar in size as the recess inside the door jamb However, moderate forces can still break the door jamb even with different size strike plates installed
Numerous door reinforcement assemblies have been invented in order to protect doors and prevent breaking of a door jamb Many of the reinforcements are variations of the strike plate. These types of reinforcements are mainly fastened to the bolt receiving face of the jamb For instance, U.S. Pat. No. 5,456,507 issued to Jones discloses a strike plate assembly having numerous pins that extend through the door jamb and into the door support structure behind the door jamb. U.S. Pat. No. 5,241,790 issued to Schimpf disclosed a plate mounted on the face of the jamb, in the space between the jamb and the door frame. In order to install the reinforcing plate behind the door jamb, the interior trim strip is removed from the door frame and the reinforcing plate is mounted behind the door jamb Some of the door reinforcement assemblies are fastened to the sides of the jamb U.S. Pat. No. 4,074,484 issued to Queren, discloses a plate which is screwed to the wall studs and the door frame side rail. If a door is struck hard, the screws will pop and door opens Reinforcements can also be affixed to both the face and the sides of the jamb For instance, U.S. Pat. No. 6,857,672 issued to Drew discloses a U shaped piece which is installed on the face of the jamb The sidewalls which extent to the sides of the jamb include holes for fastening the piece to the door frame. U.S. Pat. Nos. 6,085,465, 6,305,127 and 6,430,876 issued to Olberding disclose a strike plate with an additional plate projected transversely from the flat surface plate Said transverse projection locates alongside of the door jamb and it can be screwed into the door jamb for reinforcement U.S. Pat. No. 5,566,509 issued to Long discloses an elongated reinforcement strip having an L-shaped transverse cross-section of one short leg and one long leg, the long leg for mounting on a door jamb face and the short leg for mounting on a door jamb edge U.S. Pat. No. 4,858,384 issued to Blankenship discloses an elongate support plate having an L-shaped cross section with a first side to overlap the inside of a door jamb and a second side to overlap the front of a door jamb. And U.S. Pat. No. 5,070,650 issued to Anderson discloses a flat elongate metal plate adapted to overlie a portion of the inner bolt receiving face of a door jamb and a thin elongate metal plate having an L-shaped cross-section and including a first side adapted to overlie the first metal plate and a second side adapted to be slidably inserted beneath the decorative molding and the outer face of the door jamb.
U.S. Pat. No. 4,416,087 issued to Ghatak, discloses reinforcing rods positioned internally along the depth of a door jamb adjacent the bolt receiver or striker plate. The rods use a brace bar positioned on the edge of the door jamb. The brace bar is exposed once the door is opened. Ghatak's invention requires modification of the door frame in order to be installed. The door trim must be removed, the bars are installed, then modification to the door trim is made, and then the modified trim is re-attach to the door jamb. In addition, it is not concealed, located between the door jamb and door trim, and will be obvious from the outside once the door is opened.
One advantage of the present invention over the prior art is that once installed, the device is concealed and therefore cannot be seen from the outside But its more important advantage is that there is no need to make any major modifications to the exiting door assembly. It can be installed on any wooded door jamb without removing any part of the door frame, door jamb or its decorative trim.
The prior art taken either singly or in combination, is seen to describe the instant invention as claimed.